The present invention generally relates to respirators, and more particularly, to a half-mask respirator including a head harness assembly having pairs of upper and lower straps connected to a strap support.
Half-mask respirators (sometimes referred to as xe2x80x9cface masksxe2x80x9d) are worn over the mouth and nose, but not eyes, of a person for two common purposes: (1) to prevent impurities or contaminants from entering the wearer""s breathing tract; and/or (2) to protect others from being exposed to pathogens and other contaminants exhaled by the wearer. In the first situation, the respirator is worn in an environment where the air contains particles harmful to the wearer, for example, in an auto body shop. In the second situation, the respirator is worn in an environment where there is a high risk of infection, for example, in an operating room.
To accomplish either of these purposes, a snug fit to the wearer""s face must be maintained. The desired fit is achieved in many half-mask respirators by using a pair of straps, with a first strap extending laterally from the respirator body around the back of the wearer""s head above the ears and a second strap extending laterally from the respirator body around the back of the wearer""s neck.
One problem with this design is that the strap that extends around the wearer""s neck can irritate the wearer. The irritation is caused by the strap rubbing against the wearer""s skin as the wearer""s head rotates from side-to-side. That irritation is undesirable because of the negative affect it can have on the wearer""s motivation to use the respirator as directed. For example, if the lower strap is loosened to reduce the irritation, improper tension from strap may exert forces that skew the mask from its intended wearing configuration. This can cause leaks around the respirator perimeter, creating potential safety concerns.
The present invention provides a half-mask respirator that is retained on a wearer""s head by a head harness assembly including upper and lower straps and a strap support. The upper and lower straps connect to the strap support at upper and lower strap attachment points on each side of the strap support. The distances between the attachment points on each side of the strap support are fixed when the strap support is located on the wearer""s skull and the half-mask respirator is mounted over the wearer""s nose and mouth. Because the distances between the upper and lower straps are fixed by the strap support, the lower strap can be supported above the wearer""s neck to eliminate a potential source of discomfort for the wearer.
The respirator body of the half-mask respirators of the invention can take many different forms. For example, the respirator body can be provided in a drop down configuration that may or may not include a carriage. The respirator body may be provided in the form of a porous filtering face mask or it may be a respirator including a non-porous body and filter cartridges.
In all embodiments, however, the half-mask respirators of the invention include the strap support and upper and lower straps in a configuration that removes the lower strap from the back of the wearer""s neck when the half-mask respirator is in position over the wearer""s nose and mouth.
In those embodiments in which at least one pair of support straps is removably attached to the strap support, one advantage of the present invention is that the respirator body is capable of being retained at multiple positions without completely removing the half-mask respirator. The respirator body is able to be retained at a first position covering the nose and mouth of the wearer and at a second position dropped down from the face of the wearer without moving the strap support from the head of the wearer. The half-mask respirator may hang near the user""s body in the dropped down position. This is advantageous in situations where the user needs access to his or her mouth and does not have to take the time to set the half-mask respirator down and re-don the half-mask respirator when needed. Also, the half-mask respirator is out of the user""s way when hanging near the body, thereby allowing substantially unobstructed working conditions. This flexibility saves time and protects the half-mask respirator and accompanying filters from contamination. In addition, the half-mask respirator is easily adjusted and conforms to multiple facial configurations.
Another advantage is that the half-mask respirator may be retained against the face of the wearer at four points by the upper and lower straps of the head harness assembly. Such a four point seal can provide greater protection against contaminants.
In brief summary, in one aspect, the present invention provides a half-mask respirator that includes a body configured to cover the nose and mouth of the wearer. The respirator also includes a strap support located on the wearer""s skull when the respirator body is in position over the nose and mouth of the wearer. The respirator body is held in place by at least two upper straps that extend from opposite sides of an upper portion of the respirator body to opposing sides of the strap support, the upper straps connected to the strap support at upper strap attachment points. Also holding the respirator body in place are at least two lower straps that extend from opposite sides of a lower portion of the respirator body to opposing sides of the strap support, the lower straps connected to the strap support at lower strap attachment points. The distances between the upper and lower strap attachment points on each opposing side of the strap support are fixed when the strap support is located on the wearer""s skull and the respirator body is in position over the nose and mouth of the wearer. As a result, the lower straps do not extend around the back of the wearer""s neck.
In brief summary, in another aspect, the present invention provides a halfmask respirator that includes a body configured to cover the nose and mouth of the wearer. The respirator also includes a support crown located on the wearer""s skull when the respirator body is in position over the nose and mouth of the wearer. The respirator body is held in place by at least two upper straps that extend from opposite sides of an upper portion of the respirator body to opposing sides of the support crown, the upper straps connected to the support crown at upper strap attachment points. Also holding the respirator body in place are at least two lower straps that extend from opposite sides of a lower portion of the respirator body to opposing sides of the support crown, the lower straps connected to the support crown at lower strap attachment points. The distances between the upper and lower strap attachment points on each opposing side of the support crown are fixed when the support crown is located on the wearer""s skull and the respirator body is in position over the nose and mouth of the wearer. As a result, the lower straps do not extend around the back of the wearer""s neck. Additionally, the lower straps are connected to the respirator body below support crown when the support crown is located on the wearer""s skull and the respirator body is in position over the nose and mouth of the wearer.